Update bosh3.py

Author: patrick-kidger

diffrax/solver/bosh3.py

@@ -22,8 +22,7 @@ class Bosh3(AbstractERK):
     3rd order explicit Runge--Kutta method. Has an embedded 2nd order method for
     adaptive step sizing.
 
-    Also sometimes known as "Heun's third order method". (Not to be confused with
-    [`diffrax.Heun`][], which is a second order method).
+    Also sometimes known as "Ralston's third order method".
     """
 
     tableau = _bosh3_tableau